import java.util.Arrays;
import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: ${USER}
 * Date: ${YEAR}-${MONTH}-${DAY}
 * Time: ${TIME}
 */
public class Main {
    @Override
    public String toString() {
        return "Main{}";
    }

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        System.out.println("请输入字符串：");
        String str = scan.nextLine();
        findChar(str);
    }
    public static void findChar(String str) {
        int n = 0;
        for (int i = 0; i < str.length(); i++) {
            boolean flag = false;
            for (int j = 0; j < i; j++) {
                if(str.charAt(i) == str.charAt(j)) {
                    flag = true;
                }
                }
            if(!flag) {
                System.out.print(str.charAt(i));
            }
        }
    }
}